TWI746632B - Process for extracting safety screw for motor vehicle wheels, extractor and set of tools for executing the process and use of the extractor and set of tools - Google Patents

Abstract

The invention relates to an extractor (1), a process and a set of tools for extracting a safety screw or a broken screw, consisting of inserting an extractor (1) into a hollowed bore (17) in said screw, by inserting the cogged rod (3) of the extractor (1) into said bore (17) and by percussion on the head (7) of said extractor (1) using a percussion tool (49), so as to couple the extractor (1) and the screw (13) in rotation; and extraction of the screw (13) by loosening it using a key suitable for with the head (7) of the extractor.

Description

Method for removing safety screws for wheels, extractor and tool set for carrying out the method, and use of the extractor and tool set

The present invention is in the field of methods and tools used in automobile mechanics, especially related to methods and tools used to disassemble wheels, for example, disassembly of motor vehicles.

The conventional wheel assembly of a vehicle uses a plurality of screws to assemble the wheel on the hub, and one of the screws is a security screw or an anti-theft screw. These security screws are also called "anti-dismantling" screws, and they come in various forms. Therefore, it is well known that the heads of these security screws do not conform to the mold cavity of standard keys, resulting in the need to use a special tool with a key suitable for the heads of the security screws in order to be able to loosen the screws.

This special tool is usually found in the vehicle. However, the tool may be lost or damaged, making it impossible for the vehicle user to replace the wheel when the tire blows out. Then, the user must call a professional technician who has the correct tools or must find a solution to remove the security screw. The special cavity on the screw head may also be damaged and cannot be used, or the tool has broken on the screw head and remains partially fixed to the screw head, so that the special cavity is no longer usable.

One of the solutions performed by a technician to loosen the screw and thus replace the wheel is to weld another hex head screw (standardized) to the head of the safety screw so that the hex head screw is rotationally coupled with the screw. The assembly thus formed has a head which can be operated with standard tools for loosening the safety screw.

Unfortunately, this technique has several disadvantages, including thermal damage to the paint and varnish of the rim, or the risk of breaking the safety screw head in the case of a shear head screw.

Finally, this technology is not suitable for situations where the head of a safety screw is designed to rotate freely without a suitable tool for clamping the head (counterbore), such as the safety device described in European Patent EP2228176 .

The methods and tools used to remove broken screws are, for example, those described in European Patent No. EP0451256. This extractor is in the form of a screw rod with left-handed counter-thread, and is usually conical. Insert the screw rod into a hole made in the screw to remove the screw. Unfortunately, these solutions are not suitable for disassembly of safety screws, especially safety screws used on wheels, because the threads of these screws are fragile or their insufficient contact surface prevents users from applying sufficient torque. To loosen the screw. The safety screw on the wheel may have a tightening torque of 160N.m or more.

Therefore, there is a need for a method and tool for removing safety screws, which are suitable for different types of safety screws, and can also be used on screws. When the wire is broken or damaged, or when the screw has a shear head or is designed to rotate freely. There is also a need for an extraction method and tools so that the broken safety screw can be removed without damaging the components around the screw. There is a need for a method and tool for removing safety screws, which are suitable for disassembling wheels, and which can therefore be used for screws with high tightening torque.

The purpose of the present invention is to solve at least one of the disadvantages of the prior art by providing a method and tool for disassembling wheels. The tools are generally acceptable because they can be used in different types of safety screws or Broken screw.

For this purpose, and according to a first aspect, the object of the present invention relates to a method of taking out a safety screw or breaking a screw, the screw comprising a rod, and the method is characterized in that it comprises the following steps: a) using a diameter smaller than the A drill with the diameter of the screw shaft, drill a hole longitudinally in the screw; b) Assemble an extractor in the hole, the extractor includes a toothed rod and a head, the tooth system of the toothed rod is In the form of a longitudinal rib, the head is fixed to one of the ends of the rod, and the assembly is performed by inserting the rod of the extractor into the hole and hitting the head of the extractor with a beating tool Obtained, so that the extractor and the screw are rotationally coupled; c) the screw is loosened by using a key suitable for the head of the extractor, and the screw is taken out, wherein the extractor includes a sleeve, the sleeve At its head The bottom has a diameter greater than the diameter of its rod and less than the diameter of its head to form a shoulder with the rod, and wherein the pressing step (b) includes pressing the rod of the extractor into the screw until the shoulder Butt against the screw (13).

According to a particular embodiment, considering all possible combinations individually or in consideration, the method may include one or the other of the following features:

Drilling the hole (a) involves using a drill bit containing a tungsten carbide tip.

Before drilling the hole (a), there is a step in which a centering device is placed on the screw to position and guide the drill head. The assembly (b) includes the use of an impact mandrel which is placed between the extractor and the beating tool, and one end of which has a cavity suitable for the head of the extractor.

After removing (c) the screw, use a disassembly mandrel to disassemble the extractor from the screw that has assembled the extractor.

As can be understood from reading the definition provided above, the present invention consists of the following steps: replacing the safety screw head or the broken head with an extractor head that can be handled with standard tools. To achieve this, the present invention will rotatably couple the extractor with the screw to be loosened by pressing the extractor forcefully into a hole made in the screw. In the presence of a sleeve on the head and the extractor, the screw head is pressed against the head of the extractor or against the shoulder formed by the sleeve to limit the sinking of the extractor in the screw . This restriction on the sinking of the extractor rod makes it possible to constrain the rod inside the screw and prevent contact with the hub, while allowing a considerable length of rod to be pressed into the screw.

According to a second aspect, the object of the present invention is a method for The extractor for performing the above method is used to extract a safety screw or a broken screw, and is characterized in that it includes a toothed rod and a head. The tooth system of the toothed rod is in the form of a longitudinal rib, and the head is fixed to the One of the ends of the rod, and it includes a sleeve placed at the bottom of the head. The diameter of the sleeve is larger than the diameter of the rod and smaller than the diameter of the head to form a shoulder with the rod. The extractor is preferably made of steel.

The head is preferably hexagonal.

The extractor according to the present invention is remarkable in that it causes the screw to be loosened to be directly pressed with a large contact surface, so that a release torque of 160 N.m or more can be applied to loosen the screw. The sleeve presses the extractor until it abuts the head or shoulder, resulting on the one hand being able to control the sinking length of the rod and therefore forcing it not to exceed the screw rod. On the other hand, the abutment can prevent an impact when the extractor is operated, because the impact will damage the screw held in the extractor, and the head or sleeve is set to support the screw.

According to a third aspect, the object of the present invention is a set of tools for performing the above-mentioned method, characterized in that it comprises at least one extractor as described above and one or more elements selected from the following: the diameter is similar to the extractor At least one drill bit of the diameter of the rod of the device used to drill a hole in the screw; one or more centering devices used to position and guide the drill bit during drilling operations; an impact mandrel used to compress the extractor Go into a hole drilled in the screw; take out the mandrel for self-assembly of the screw with the extractor The extractor.

According to a particular embodiment, considering all possible combinations individually or in consideration, the combination according to the present invention may include one or the other of the following features:

The assembly includes at least one drill bit, and at least one of the drill bits has a tungsten carbide tip.

The assembly includes at least one centering device for positioning and guiding a drill head, and at least one of the centering devices is in the form of a truncated cone, and a center pipe penetrates the truncated head longitudinally on both sides Cone, the diameter of the conduit is larger than the diameter of the drill head and/or the extractor rod.

The assembly includes at least one centering device for positioning and guiding the drill bit, and at least one of the centering devices is in the form of a hollow socket having a cylindrical or truncated cone shape, A central pipe with a diameter larger than the diameter of the drill head and/or the extractor rod penetrates the hollow socket; the central pipe contacts an inner chamber, which opens outward at one of the ends of the body , The size of the mouth of the inner chamber is set to cover the screw head; preferably, the centering device has a protrusion on its end opposite to the opening of the inner chamber, and the protrusion replicates the extractor The shape of the head, and the duct penetrates the bump.

The assembly includes at least one centering device, and at least one of the centering devices is in the form of a cylinder, and the cylinder has at least one end portion thereof suitable for a hexagon The mold cavity of the screw head, and a central pipe penetrates the hexagonal screw head along its length, and the diameter of the pipe is larger than the diameter of the drill head and/or the extractor rod. Preferably, the cylinder has two radially opposite planes. More preferably, the centering device has a cavity suitable for hexagon head screws at each end of the centering device, and the cavity has different sizes.

At least one of the centering devices is made of plastic material, preferably polyoxymethylene (POM).

The assembly includes an impact mandrel, and the impact mandrel has a cavity suitable for the head of the extractor at one of its ends. The assembly includes a detachable mandrel with a fork with two teeth at one of its ends, and the thickness of the two teeth between their tips and their bottoms gradually increases, and preferably Ground, the two teeth are parallel to each other, and the interval between the teeth of the disassembly mandrel is smaller than the diameter of the head of the extractor.

According to a fourth aspect, the present invention relates to a use of the above-mentioned extractor or the above-mentioned combination for removing safety screws or broken screws on wheels.

1: Extractor

3: with rack

5: rib

7: head

9: Sleeve

11: Shoulder

13: Screw

15: Wheels

17: Hole

19: Drill

21: Rod

23: head

25: Centering device

27: Catheter

29: Centering device

31: Body

33: inner chamber

35: Central catheter

37: bump

39: Mould cavity centering device

41: Cylindrical socket

43: Mould cavity

45: Central catheter

47: plane

49: Mallet

51: Impact Mandrel

53: Mould cavity

55: Disassemble the mandrel

57: Fork

59: tooth

61: Tip

63: bottom

65: Jaw

From the following descriptions provided by examples and with reference to the accompanying drawings, the present invention and other aspects and advantages will be better understood, among which:

Figure 1 shows an extractor according to the invention.

Figure 2 is a cross-sectional view showing the use of the drill bit and centering device according to the present invention to drill a hole in a safety screw.

Figures 3 to 5 illustrate different centering devices according to the present invention.

Figure 6 shows the compression of the extractor according to the invention.

Figure 7 shows a disassembly mandrel according to the invention.

Figure 8 shows the removal of the extractor from the screw fitted with the extractor.

In the following description, the terms "include" and "include" are synonymous and not restrictive, where it allows other elements to be present in the device or the vehicle it refers to. What is understood is that the term "understanding" includes the word "composition".

In this description, the method according to the present invention will be described at the same time as the tool according to the present invention used to execute the method.

Reference is first made to Fig. 1, which shows an extractor 1 for performing a method of extracting a screw, such as a safety screw or a broken screw. The extractor 1 according to the present invention includes a toothed rod 3 whose teeth in the form of protruding ribs 5 extend longitudinally along the length of the toothed rod 3 so that a transverse section of the rod shows a star-shaped pattern. The extractor 1 also has a head 7, which is preferably hexagonal, so that it can be operated using standard keys. The extractor 1 is preferably made of steel. The head 7 and the toothed rod 3 are irreversibly fixed to each other, so that when the toothed rod 3 is pushed into the screw, the head can be used as abutment to limit the sinking of the extractor and as a support to avoid operation The impact, as seen below.

According to the present invention, the extractor 1 includes a sleeve 9 arranged at the bottom of the head 7 and having a diameter larger than the diameter of the toothed rod 3 and smaller than the diameter of the head 7 to form a shoulder 11 with the toothed rod 3 .

The method according to the present invention includes the following steps: a) Use a drill with a diameter smaller than the diameter of the screw shaft, and wait A hole is drilled longitudinally in the loosened screw; b) Assemble an extractor in the hole. The extractor includes a toothed rod and a head. The tooth system of the toothed rod is in the form of longitudinal ribs, The head is fixed to one of the ends of the rod, and the assembly is obtained by inserting the rod of the extractor into the hole and hitting the head of the extractor with a beating tool, so that The extractor is rotatably coupled with the screw; c) the screw is taken out by loosening the screw with a key suitable for the head of the extractor.

The drilling of a hole a) is shown in FIG. 2 in the condition of the extraction screw 13 called "retractable", in which it is placed at the bottom of the cavity provided by the wheel rim 15. This step therefore consists of drilling a hole 17 longitudinally in the screw 13 to be loosened using a drill bit 19 having a diameter smaller than the diameter of the rod 21 of the screw 13. In the figure, the safety screw shown has a head 23. The drilling operation is in progress and the hole has not yet reached the shaft of the screw. However, in the method according to the present invention, the shaft of the screw becomes hollow along all or part of its length. For example, the length of the hole made in the screw is greater than 10 mm, for example, between 10 and 20 mm, depending on the type of screw under consideration. The length of this hole will result in an extractor that can be placed, its rod has a corresponding length, and it then provides a large contact surface. This large contact surface will allow enough torque to be applied to loosen the screw.

The drilling is performed using the drill 19. Preferably, the drilling of the hole (a) is performed using a drill bit containing a tungsten carbide tip. This drill bit can be obtained, for example, by cutting the tip of a conventional steel drill bit to insert a tungsten carbide insert therein. The use of this bit is convenient when the safety screw is hardened Drill holes for safety screws when made of steel.

According to the present invention, the diameter of the drill bit is equal to the diameter of the extractor rod, so that the rod can be assembled and held in the hollow hole in the screw.

It will be appreciated that with respect to the head 23, the hole 17 must be in the center, as it then extends into the shaft 21 of this screw. According to a preferred embodiment of the present invention, and as shown in FIG. 2, the drilling (a) of the hole is performed using a centering device 25 for positioning and guiding the drill head.

Depending on the type of screw to be loosened, the centering device can have different shapes. In the example shown in Figure 2, the screw is a "retractable" screw because it is placed at the bottom of the cavity provided by the rim. The centering device 25 with a "retractable screw" is preferably a truncated cone. In the form of a cone, a central tube penetrates it longitudinally on both sides. This centering device is shown in Figure 3. The guide tube 27 has a diameter larger than the diameter of the drill bit, and is intended to be used for positioning and guiding the drill bit.

Figure 4 shows a centering device 29 for centering and guiding a drill bit in the case of an "overwrapped" screw according to the present invention, where the screw appears on the rim. Then, the centering device 29 equipped with an "overcoated screw" will be in the form of a hollow sleeve. A cylindrical or frustoconical body 31 and a center tube 35 pass through the hollow sleeve and contact the end of the body 31. One of the inner chambers 33 that is open to the outside. Preferably, the inner chamber 33 has an inner conical shape, so that its diameter gradually decreases from its mouth along its length. This configuration will allow the centering device to cover the screw head and hold it on the latter. A central guide tube 35 having a diameter larger than the diameter of the drill rod (then the extractor rod) is used for positioning and guiding the drill. Preferably, the centering device 29 has an end opposite to an opening in the inner chamber 33 The bump 37 replicates the shape of the head of the extractor, and the tube 35 penetrates the bump 37. The protrusion 37 allows the user to use an impact mandrel to position and press the centering device 29 on the screw head.

In the case where the screw head is installed as a free rotation (counter head), for those who specialize in this technology, it is advantageous to use a cavity centering device 39 as shown in FIG. 5. The cavity centering device is in the form of a cylindrical socket 41, and at least one of its ends has a cavity 43 that fits the shape of the head of a hexagonal screw. The body 41 has a central duct 45 extending longitudinally through it on both sides. The guide tube 45 has a diameter larger than the diameter of the drill rod (then the extractor rod), and is used for positioning and guiding the drill. The cavity 43 will hold the screw head in position and prevent the screw head from rotating under the action of the drilling force during the drilling operation. Preferably, the main body 31 has two radially opposed flat surfaces 47 to facilitate holding and positioning the centering device. More preferably, the centering device has a cavity suitable for hexagon head screws at each end of the centering device, and the cavity has different sizes.

According to a preferred embodiment of the present invention, at least one of the centering devices is made of plastic material, such as polyoxymethylene (POM), to limit the risk of damaging the paint and varnish of the rim. However, metal materials can also be used to make them.

Once the hole has been made, the extractor can be placed in position according to the invention. For this purpose, during the pressing operation b) depicted in Figure 6, the extractor rod is pressed into the hole. The assembly is performed by sliding longitudinally along the hole, and this sliding is produced by hitting a hammer, such as a hammer, on the head of the extractor. The assembly of the extractor into the screw will make the extractor and the screw rotationally coupled.

According to a preferred embodiment of the present invention, the assembly step (b) is performed by placing an impact mandrel 51 between the extractor 1 and the hammer 49. The impact mandrel 51 according to the present invention includes an end portion having a cavity 53 suitable for the head 7 of the extractor 1. The use of this mandrel results in the extractor being supported in position for its assembly.

Preferably, when the extractor has a sleeve 9 and the sleeve 9 bears against the shoulder 11 formed by the sleeve 9 and the toothed rod 3, the extractor 1 is assembled until the bottom of its head abuts the screw的头23. The sinking of the extractor 1 is restricted so as to ensure that the toothed rod 3 is retained in the rod 21 of the screw 13. If the extractor rod protrudes from the end of the screw rod, it will be attached to the hub, which will make the loosening of the screw more difficult.

Once the extractor is positioned, the screw is removed by loosening the screw using a key suitable for the head of the extractor, which is performed during the extraction c) (not shown). The straightness of the assembly associated with the extended contact surface results in a release torque of at least 160 N.m, which is required to release the safety screw from the wheel.

According to a preferred embodiment of the present invention, after the screw is removed (c), the extractor is removed from the screw on which the extractor has been assembled (d), preferably using a removal mandrel 55 as shown in FIG. 7. The separation of the screw 13 from the extractor 1 results in that the extractor 1 can be reused for the extraction of another screw 13. When the extractor 1 has a sleeve 9, which defines a space between the head 23 of the screw 13 and the head 7 of the extractor 1, so that the disassembly operation can be performed.

Preferably, the detachment mandrel 55 has a fork 57 with two parallel teeth 59 at one of its ends, the thickness of the two teeth 59 gradually increasing between their tip 61 and their bottom 63, Remove the teeth 59 of the mandrel 55 The interval between is selected to be larger than the diameter of the sleeve 9 and smaller than the diameter of the extractor head 7. In the case of disassembling the mandrel for use in an extractor without a sleeve, the spacing between the teeth of the mandrel must be greater than the diameter of the extractor's rod.

Step d) is shown in Figure 8. It can be seen that the screw 13 is held by the jaw 65 of a vise. The disassembly mandrel 55 is positioned to place the sleeve of the extractor 1 between its teeth 59. Then, the sleeve is pressed between the teeth 59 of the fork by beating. Because the tooth 59 has an increasing height, which is greater than the height of the sleeve at the bottom of the tooth, the sinking of the extractor 1 will lift the extractor 1 to partially remove it from the screw 13.

1: Extractor

3: with rack

5: rib

7: head

9: Sleeve

11: Shoulder

Claims (18)

A method for removing a safety screw or breaking a screw. The screw (13) includes a rod (21) and possibly a head (23). The method is characterized in that the method includes the following steps: a) Use a screw with a diameter smaller than that (13) A drill (19) with the diameter of the rod (21), drill a hole (17) longitudinally in the screw (13); b) Assemble an extractor (1) in the hole (17) , The extractor (1) includes a toothed rod (3) and a head (7), the tooth system of the toothed rod (3) is in the form of a longitudinal rib (5), and the head (7) is fixed To one of the ends of the toothed rod (3), the assembly is performed by inserting the toothed rod (3) of the extractor (1) into the hole (17) and using a beating tool (49) ) Is obtained by tapping on the head (7) of the extractor (1), so that the extractor (1) and the screw (13) are rotationally coupled; c) by using a head suitable for the extractor ( The key of 7) loosens the screw (13), and takes out the screw (13), wherein the extractor (1) contains a sleeve (9), and the sleeve (9) is located on its head (7) The bottom of the toothed rod, and the diameter is greater than the diameter of its toothed rod (3) and smaller than the diameter of its head (7), so as to form a shoulder (11) with the toothed rod (3), and wherein the pressing step (b) Including pressing the toothed rod (3) of the extractor (1) into the screw (13) until the shoulder (11) abuts the screw (13), and the assembly (b) includes using a Impact mandrel (51), the impact mandrel (51) is placed between the extractor (1) and the beating tool (49), and one end of it has a head (7) suitable for the extractor (1) The cavity (53). The method of claim 1, wherein drilling the hole (17)(a) includes using a drill bit (19) containing a tungsten carbide tip. Such as the method of claim 1, wherein there is a step before drilling the hole (17)(a), in which a certain central device (25, 29, 39) is placed on the screw (13) to position and guide the drill ( 19). Such as the method of claim 1, wherein after removing the screw (13)(c), a disassembly mandrel (55) is used to disassemble the extractor (1) from the screw (13) that has assembled the extractor. An extractor for performing the method of claim 1, characterized in that the extractor includes a toothed rod (3) and a head (7), and the teeth (5) of the toothed rod (3) are In the form of a longitudinal rib (5), the head (7) is fixed to one of the ends of the toothed rod (3), and the extractor also includes a set placed at the bottom of the head (7) A barrel (9), the diameter of the sleeve is larger than the diameter of the toothed rod (3) and smaller than the diameter of the head (7), so as to form a shoulder (11) with the toothed rod (3). A tool set for performing the method of claim 1, characterized in that the tool set includes at least one extractor (1) such as claim 5 and one or more elements selected from the following: the diameter is similar to the extractor ( 1) The drill bit (9) with the diameter of the toothed rod (3), used to drill a hole (17) in the screw (13); used to locate and guide the drill bit (19) during the drilling operation Centering device (25, 29, 39); an impact mandrel (51) for pressing the extractor (1) into the hole (17) drilled in the screw (13); a disassembly mandrel (55) , Used to self-assemble the screw with the extractor (1) Take out the extractor (1) from the wire (13). The tool set of claim 6, wherein the assembly includes at least one drill bit (19), and at least one of the drill bits (19) has a tungsten carbide tip. The tool set of claim 6, wherein the assembly includes at least one centering device (25) for positioning and guiding the drill bit, and at least one of the centering devices (25) is in the form of a truncated cone A central pipe (27) penetrates the truncated cone longitudinally on both sides, and the diameter of the pipe (27) is larger than the diameter of the drill bit (19). Such as the tool set of claim 6, wherein the assembly includes at least one centering device (29) for positioning and guiding the drill bit, and at least one of the centering devices (29) is a hollow socket Form, the hollow socket has a cylindrical or frusto-conical shape, a central pipe (35) with a diameter larger than the diameter of the drill bit (19) penetrates the hollow socket; the central pipe (35) contacts an inner chamber ( 33), the inner cavity (33) is open to the outside at one of the ends of the body (31), and the size of the mouth of the inner cavity (33) is set to cover the screw head. Such as the tool set of claim 9, wherein the centering device (29) has a protrusion (37) on its end opposite to the opening of the inner chamber (33), and the protrusion (37) replicates the removal The shape of the head (7) of the device (1), and the catheter (35) penetrates the protrusion (37). For example, the tool set of claim 6, wherein the assembly includes at least one centering device (39) for positioning and guiding the drill bit, and at least one of the centering devices (39) is cylindrical (41) ), the cylinder (41) has a cavity (43) suitable for the head of a hexagonal screw on at least one end of it, and a central duct (45) penetrates along its length The diameter of the head of the hexagonal screw and the pipe (45) is larger than that of the drill bit (19). Such as the tool set of claim 11, wherein the cylinder has two diametrically opposed planes. Such as the tool set of claim 6, wherein the assembly includes at least one centering device (25, 29, 39) for positioning and guiding the drill bit, and at least one of the centering devices (25, 29, 39) Those are made of plastic materials. Such as the tool set of claim 6, wherein the combination includes an impact mandrel (51), and the impact mandrel (51) has a head (1) suitable for the extractor (1) at one of its ends 7) The cavity (53). Such as the tool set of claim 6, wherein the assembly includes a disassembly mandrel (55), and the disassembly mandrel (55) has a fork (57) with two teeth (59) at one of its ends , The thickness of the two teeth (59) between their tip (61) and their bottom (63) gradually increases. Such as the tool set of claim 15, wherein the two teeth are parallel to each other, and the interval between the teeth (59) of the disassembly mandrel (55) is smaller than the diameter of the head (7) of the extractor (1). A use of the extractor as in claim 5, used to extract safety screws or broken screws on wheels. A use of the tool set as in claim 6, used to remove safety screws or broken screws on wheels.

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